I had forgotten about OEIS! Anyway Ithink the actual number might be 1577 rather than 1617 (this also gives no answers). I was only assuming agnosticism over factors in the overlap region ABCD if all pairs AB,AC,...,CD had factors, but I think that is missing some examples. My current guess is that any overlap region like ABCD should be agnostic iff all of the overlap regions “surrounding” it in the Venn diagram (ABC, ABD, ACD, BCD) in this situation either have a factor present or agnostic. This gives the series 1, 2, 15, 1577, 3397521 (my computer has not spat out the next element). This also gives nothing on the OEIS.
My reasoning for this condition is that we should be able to “remove” an observable from the system without trouble. If we have an agnosticism, in the intersection ABCD, then we can only remove observable B if this doesn’t cause trouble for the new intersection ABD, which is only true if we already have an factor in ABD (or are agnostic about it).
I had forgotten about OEIS! Anyway Ithink the actual number might be 1577 rather than 1617 (this also gives no answers). I was only assuming agnosticism over factors in the overlap region ABCD if all pairs AB,AC,...,CD had factors, but I think that is missing some examples. My current guess is that any overlap region like ABCD should be agnostic iff all of the overlap regions “surrounding” it in the Venn diagram (ABC, ABD, ACD, BCD) in this situation either have a factor present or agnostic. This gives the series 1, 2, 15, 1577, 3397521 (my computer has not spat out the next element). This also gives nothing on the OEIS.
My reasoning for this condition is that we should be able to “remove” an observable from the system without trouble. If we have an agnosticism, in the intersection ABCD, then we can only remove observable B if this doesn’t cause trouble for the new intersection ABD, which is only true if we already have an factor in ABD (or are agnostic about it).